Simulated reflector lamp using par lamp components

ABSTRACT

A reflector lamp unit is provided having a light source which is capable of meeting the efficiency requirements mandated by law. The reflector lamp unit includes a pressed glass reflector member having a curved portion and a lower neck portion on which is secured a conventional threaded screw base. The light source can be a high efficiency light source such as a discharge light source of a tungsten-halogen light source contained within a pressurized lamp envelope. The light source is disposed within the curved portion of the reflector member at a position along the longitudinal axis and ahead of the optical focal point of the reflector. In this manner, a beam pattern is generated which is widely scattered and unfocused as compared to that beam pattern which would be produced from a light source disposed at the focal point. The reflective surface of the curved portion of the reflector member is lightly roughened thereby resulting in an increased diffusion characteristic of the beam pattern. A spacer member is disposed within the lower portion of the reflector member to provide both a means for enclosing the inner space of the reflector and for providing support for the light source.

This application is a continuation of application Ser. No. 08/134,038,filed Oct. 8, 1993, now abandoned.

FIELD OF THE INVENTION

This invention relates to a reflector lamp configuration which isachieved using components constructed for use with parabolic aluminizedreflector (PAR) lamps. More particularly, this invention relates to sucha reflector lamp which utilizes PAR configured components so as toachieve improved energy efficiency properties yet simultaneously,provide the same beam pattern output as a lamp which utilizesconventional reflector lamp components.

BACKGROUND OF THE INVENTION

Reflector ("R") lamps and PAR lamps are commonly used in variouscommercial, industrial and residential lighting applications dependingon the specific beam performance characteristics desired. For instance,although both types of lamps can provide typical floodlight or spotlightperformance in both outdoor as well as indoor environments and at shortto medium distances, it is known that the PAR type of lamp is moreefficient and provides a tighter, more defined beam pattern with muchhigher center beam and/or peak CP (e.g. candle power) than an R lamp andis therefore utilized in display and accent applications. R lamps on theother hand are utilized in applications where it is desired to have amore diffuse, wider beam pattern and thus finds more general acceptancein residential applications. Regardless of the application, however, byOctober, 1995 both types of lamps will be subjected to the requirementsof recently enacted legislation mandating an improvement in the efficacy(e.g. lumens per watt--"lpw") of certain lighting products.Specifically, the Energy Policy Act of 1992 has set certain limits,which in the case of the R lamp, will preclude the use of a conventionalC-7 type of filament typically utilized as the means for generatinglight output. Instead of a bare filament disposed within a blownreflector envelope as is the present configuration for an R lamp,lighting manufacturers must substitute a more energy efficient lightsource. An example of such a light source is described in U.S. Pat. No.4,959,583 issued to Arsena et al on Sep. 25, 1990 and issued to the sameassignee as the present invention wherein a tungsten halogen lightsource is utilized in a compact PAR lamp. Of course, a further moreefficient light source would be one wherein the tungsten halogen lightsource had an interference coating disposed thereon so as to reflectinfrared radiation back upon the filament to thereby improve theefficiency. Such a halogen-IR light source is presently available fromGeneral Electric Company's Lighting Business in a variety of productsincluding PAR lamps. Further examples of tungsten halogen light sourcesused in conjunction with PAR lamps can be found in U.S. Pat. Nos.4,829,210 and 5,057,735. In each of these patents, a tungsten halogenlamp is mounted within a pressed glass PAR reflector having a covermember disposed thereover.

Although in theory the concept of inserting into a blown glass reflectorenvelope, a tungsten halogen light source including the hollowcylindrical lamp envelope associated therewith, seems prudent forpurposes of improving the energy efficiency of an R lamp, because such alight source is contained within a pressurized lamp envelope, safetyconsiderations dictate that this type of light source can not beutilized in a typical glass reflector of an R lamp. Accordingly, itwould be desirable to provide an alternate configuration forconventional R lamps that would meet the necessary energy efficiencylevels required by the Energy Policy Act of 1992 and yet still providethe wider, more diffuse beam pattern of an R lamp. In other words, giventhat PAR lamps as shown in the previously referenced U.S. Pat. No.4,959,583 can meet the energy efficiency levels required, it would beadvantageous if a configuration could be provided that would render Rlamps compliant with the Act and therefore avoid the possibility ofeliminating R lamps from the marketplace entirely.

One approach to improving the energy efficiency of existing R lampswould be to include as an additive to the fill material contained withinthe blown glass reflector, an amount of the rare gas Krypton. It isknown in the art that such a modification will achieve improved energyefficiency using existing filament structures; however, thismodification is limited in the practical sense for commercial reasons.The rare gas Krypton is expensive and would be required in such largequantities particularly at higher wattage R lamp products, that to relyon this approach would render the resultant product commercialnon-viable. Therefore, although adding krypton would be potentiallyeffective in improving the energy efficiency of a conventional R lamp,it would be more advantageous to provide an improved energy efficiencyapproach that was more cost effective thus insuring the continued marketacceptance of such an R lamp.

SUMMARY OF THE INVENTION

The present invention provides an alternate configuration for achievingthe performance of a conventional R lamp while also attaining improvedenergy efficiency so as to meet the requirements of the Energy PolicyAct of 1992. Moreover, the present invention achieves such an alternateconfiguration by utilizing techniques which are cost effective therebyinsuring market acceptance of such alternative, energy efficient R lamp.

In accordance with the principles of the present invention, there isprovided a reflector lamp unit which includes an energy efficient lightsource contained within a pressurized lamp envelope and a reflectormember configured having a curved upper portion terminating in an openend, and a longitudinally extending lower portion. The reflector memberhas a reflective coating disposed thereon and has an optical focal pointassociated with the curved portion thereof. An electrically conductivescrew base is mounted on the lower portion of the reflector and is inelectrically coupled relation to the light source so as to enableenergization of the light source. A light transmissive cover member isdisposed over the open end of the reflector member. The pressurized lampenvelope is accurately mounted along the longitudinal axis of thereflector member at a position that places the light source between theoptical focal point and the open end of the curved portion of thereflector member. By precisely positioning the light source ahead of theoptical focal point, the reflector lamp achieves a beam pattern lightoutput which is wide and unfocused in comparison to a beam pattern aswould be output if the light source were disposed at the focal point.This wide and unfocused beam pattern can then be further smoothed with alens cover member thereby accurately simulating the light output of an Rlamp.

In one embodiment of the invention, the reflective coating of thereflector member is lightly roughened or textured so that the resultantbeam pattern light output is made more diffuse and further simulates anR lamp beam pattern light output.

BRIEF DESCRIPTION OF THE INVENTION

In the following detailed description, reference will be made to theattached drawings in which:

FIG. 1 is an elevational view in section of a conventional R lampconstructed in accordance with prior art teachings.

FIG. 2 is an elevational view in section of an R lamp constructed inaccordance with the teachings of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

As seen in FIG. 1, an R lamp 10 constructed in a conventionalconfiguration, includes a blown glass reflector member 12 having acurved reflector portion 14 closed by an integral flattened face portion16 having less curvature than reflector portion 14. Reflector member 12also includes a longitudinally extending neck portion 18 which tapers soas to allow mounting of a screw base member 20. For a conventional Rlamp 10 such as shown in FIG. 1, a reflective coating 22 is disposed ona portion of the inner surface primarily defined by the curved reflectorportion 14 and a portion of the neck portion 18; the flattened faceportion 16 which has no reflective coating thereon, is defined by thedividing line a shown in FIG. 1.

A filament/support structure 24 is disposed within reflector member 12substantially along the longitudinal axis 26 thereof. Thefilament/support structure 24 is one typically referred to as a C-7Afilament and includes a glass support member 28 on which a loopedfilament 30 is mounted. Support wires 32 extending from the top portionof glass support member 28 support filament 30 at various points alongthe length thereof. The ends of filament member 30 are connected to leadwires 34 which are in turn electrically connected to the screw basemember 20 in a conventional manner so as to allow for the energizationof the filament 30. In such a conventional R lamp 10, the filament 30 isdisposed at approximately the focal point of the curved reflectorportion 14 so as to provide the necessary beam pattern light outputdesired for the R lamp.

It is to be understood that the R lamp 10 of FIG. 1 is illustrational ofthe conventional construction for such a lamp; however, there are avariety of different configurations that can be provided. For instance,rather than a C-7A filament structure, it would be possible to utilize adifferent filament structure for an R lamp having a different powerrating requirement. Additionally, some conventional R lamps can havemultiple curved portions on the reflector member; for instance, see thereflector lamp illustrated in FIG. 5 of U.S. Pat. No. 4,494,176 issuedto Sands et al on Jan. 15, 1985, assigned to the same assignee as thepresent invention, and hereby incorporated by reference.

Each of the examples of conventional types of R lamps utilizes a blownglass reflector member which can be mass produced typically on anautomated high speed glass ribbon machine using a process such asdescribed in U.S. Pat. No. 4,569,867 issued to Raymond J. Noe on Feb.11, 1986 and assigned to the same assignee as the present invention.Though such a blown glass reflector member has proven acceptable for usewith a light source such as the filament structure 24 of FIG. 1, becauseof the requirements of enacted energy legislation, such a light sourcecannot meet the efficacy requirements to be effective as of Oct. 31,1995. In fact, a more energy efficient light source such as a tungstenhalogen light source would have to be substituted for use in R lamps inorder to meet the necessary efficacy constraints. Unfortunately, becausesuch a light source is provided in a pressurized envelope, given thatthe blown glass reflector member is constructed of a thin gauge of glassas compared to a pressed glass reflector as is typically used on a PARlamp for instance, safety considerations preclude the use of thecombination of a pressurized lamp envelope in a thin gauge blown glassreflector.

As seen in FIG. 2, an R lamp 40 is achieved using a reflector member 42which is constructed having a pressed glass configuration similar tothat of a PAR lamp. In fact, for the purpose of cost efficiency, itwould be possible to use a PAR reflector member to achieve the present Rlamp 40 without having to manufacture and stock separate components.Such dual utilization of common components results in savings fromavoiding the need to implement costly new automated equipment tomanufacture a separate component and, from reducing the amount ofinventory needed to manufacture the resultant PAR and R lamp endproducts. Reflector member 42 has a reflective coating 44 disposed inthe inner surface thereof. The reflective surface 44 can be a silver,aluminum or dichroic type of coating and can be applied usingconventional techniques.

Reflector member 42 is constructed of an integral body having an uppercurved portion 46 which is preferably shaped in a parabolic manner, anda lower portion 48 tapered into a narrow end region 48a on which screwbase 20 is secured. Screw base 20 can be of a conventional edison typeso as to allow insertion into ordinary fixtures. Preferably, thereflective coating 44 disposed on the inner surface of reflector member42 need not extend entirely into the lower portion 48 and the endportion 48a. Appropriate openings are formed at the end region 48a toallow for electrical coupling and for filling the inner space of thereflector lamp 40 with a fill-gas if necessary.

R lamp 40 includes a light source 50 capable of meeting the efficacyrequirements required by law. The light source 50 can be a tungstenhalogen lamp having a coiled tungsten filament 52 disposed within apressurized lamp envelope 54 having a halogen compound containedtherein. Additionally, the light source 50 may be of a tungsten halogentype which includes an interference coating disposed on the lampenvelope 54 effective so as to reflect infrared radiation back towardsthe filament 52 and improve efficiency thereby; such a light source isreferred to as a Halogen-IR light source. A further example of asuitable light source for R lamp 40 of the present invention would be adischarge type of light source which would also meet the efficacyrequirements necessary. A discharge light source, rather than having afilament disposed approximately at the position shown by filament 52 inFIG. 2, would comprise an arc discharge occupying such space. Lightsource 50 typically will have a pair of leads 56 extending from thebottom portion thereof so as to be coupled to the screw base 20 therebyallowing energization of the light source 50. A reflective disk member58 may be disposed around a pinch seal region 50a of the light source 50so that the amount of light lost through the lower region 48 of thereflector member 42, can be minimized. The reflective disk member 58 canalso be effective for redirecting heat that would otherwise flow intothe lower region 48 of the reflector 42 and is typically located at thetransition point between the curved portion 46 and the bottom portion 48of the reflector member 42.

As seen in FIG. 2, the optical focal point, designated f, resides at apoint substantially below the midpoint of the filament 52, or in thecase of a discharge lamp, below the arc discharge. In other words, thelight generating device, whether a filament 52, or an arc discharge,will reside at a point ahead of the optical focal point f, associatedwith the reflector member 42. In this manner, the characteristics of thebeam pattern output from reflector lamp 40 will be widely scattered andunfocused as compared to that beam pattern associated with a PAR lampand which can be accomplished by disposing the light source 50 at theoptical focal point f. In addition to scattering the beam pattern bydisplacing the light source 50 relative to the optical focal point f,the present invention further simulates an R lamp beam pattern bydiffusing the light beam as well. This diffusion characteristic of thebeam pattern is achieved by lightly roughening the reflective surface ofthe curved portion 46 of reflector member 42. By providing such a widelyscattered and diffused beam pattern, the reflector lamp 40 of thepresent invention effectively simulates the performance of aconventional reflector lamp but does so using a light source which willmeet the energy efficiency levels required by law and using a reflectormember 42 which can be safely used in conjunction with a pressurizedlight source 50 such as provided herein.

A spacer member 60 is provided as a means for supporting the lightsource 50 against movement away from the position whereby the optimalreflector lamp properties are achieved, and for enclosing the open end48a of the reflector member 42. Spacer member 60 includes a narrowportion 62 which is sized so as to be just larger than the diameter ofleads 56 thereby providing support for a substantial length of leadmembers 56. Spacer member 60 further includes a beveled portion whichallows for easy insertion of lead members 56 therethrough. Spacer member60 can extend the length of the lower portion 48 of the reflector member42, or it can be provided by means of stages of spacer members as seenby elements 64 and 66. By use of an appropriate securing arrangement(not shown), spacer member 60, in conjunction with a cover member 68secured to the open end of reflector member 42, can effectively providean enclosed chamber around light source 50. Cover member 68 is alsoeffective by selection of an appropriate prism configuration for furthersmoothing of the light output.

Although the hereinabove described embodiment constitutes the preferredembodiment of the invention, it can be appreciated that modificationscan be made thereto without departing from the scope of the invention asset forth in the appended claims. For instance, the light source 50 canbe mounted transverse to the longitudinal axis and still achieve thebenefits of the present invention.

I claim:
 1. A reflector lamp unit comprising:a light source containedwithin a pressurized lamp envelope, said light source having leadmembers extending therefrom; a reflector member configured so as to havea curved upper portion terminating at an open end, and a longitudinallyextending lower portion, said reflector member having a reflectivecoating disposed thereon and having an optical focal point associatedwith the curved portion thereof; an electrically conductive screw basedisposed on said lower portion of said reflective member, said lightsource being electrically coupled to said screw base so as to enableenergization of said light source; a light transmissive cover memberdisposed over said open end of said reflector member; wherein saidpressurized lamp envelope is mounted along the longitudinal axis of saidreflector member such that said light source is at a position betweensaid optical focal point and said open end of said reflector membereffective for providing a controlled divergence beam pattern lightoutput which is wide and unfocused in relation to a narrow, focused beampattern light output as occurs when said light source is positioned atsaid optical focal point; and, a spacer member disposed within saidlower portion of said reflector member, said spacer member havingthroughbores formed therein through which said lead members extend.
 2. Areflector lamp unit as set forth in claim 1, wherein said light sourceis positioned an effective distance from said optical focal point tosimulate an R lamp.
 3. A reflector lamp unit as set forth in claim 1wherein said light source is an arc discharge light source.
 4. Areflector lamp unit as set forth in claim 1 wherein said reflectivecoating disposed on said curved portion of said reflector member isroughened in texture so as to produce a diffuse light beam patternreflected therefrom.
 5. A reflector lamp unit as set forth in claim 1wherein said reflector member and said cover member are similarlyconstructed of pressed glass.
 6. A reflector lamp unit as set forth inclaim 1 wherein said throughbores are sized so as to surround a portionof said lead members in close proximity thereby providing support tosaid light source.
 7. A reflector lamp unit as set forth in claim 1,wherein said spacer member is comprised of two separate spacer elements.8. A reflector lamp unit as set forth in claim 1, wherein a center ofsaid light source is positioned between said optical focal point andsaid open end of said reflector member.
 9. A reflector lamp unit as setforth in claim 8, wherein said light source is an arc discharge type andan arc discharge is positioned between said optical focal point and saidopen end of said reflector lamp.
 10. A reflector lamp unit as set forthin claim 1 wherein said light source is a tungsten-halogen light sourcecomprising a tungsten filament disposed within said pressurized lampenvelope which contains a halogen compound therein.
 11. A reflector lampunit as set forth in claim 10, wherein a center of said tungstenfilament is positioned between said optical focal point and said openend of said reflector member.
 12. A reflector lamp unit as set forth inclaim 11, wherein said entire tungsten filament is positioned betweensaid optical focal point and said open end of said reflector lamp.
 13. Areflector lamp unit as set forth in claim 10 further comprising aninterference coating disposed on at least a portion of said lampenvelope, said interference coating being effective so that infraredradiation generated by said light source is reflected back onto saidtungsten filament.
 14. A reflector lamp unit comprising:a light sourcecontained within a pressurized lamp envelope, said light source havinglead members extending therefrom; a reflector member configured so as tohave a curved upper portion terminating at an open end, and alongitudinally extending lower portion, said reflector member having areflective coating disposed thereon and having an optical focal pointassociated with the curved portion thereof; an electrically conductivescrew base disposed on said lower portion of said reflective member,said light source being electrically coupled to said screw base so as toenable energization of said light source; a light transmissive covermember disposed over said open end of said reflector member; whereinsaid pressurized lamp envelope is mounted along the longitudinal axis ofsaid reflector member such that said light source is at a positionbetween said optical focal point and said open end of said reflectormember effective for providing a controlled divergence beam patternlight output which is wide and unfocused in relation to a narrow, beampattern light output as occurs when said light source is positioned atsaid optical focal point; and, a reflective disk member disposed arounda pinch seal region of the light source and positioned at a transitionpoint between the curved upper portion and the longitudinally extendinglower portion of the reflector member.
 15. A reflector lamp unitcomprising:a light source contained within a pressurized lamp envelope,said light source having lead members extending therefrom; a reflectormember configured so as to have a curved upper portion terminating at anopen end, and a longitudinally extending lower portion, said reflectormember having a reflective coating disposed thereon and having anoptical focal point associated with the curved portion thereof; anelectrically conductive screw base disposed on said lower portion ofsaid reflective member, said light source being electrically coupled tosaid screw base so as to enable energization of said light source; alight transmissive cover member disposed over said open end of saidreflector member; wherein said pressurized lamp envelope is mountedalong the longitudinal axis of said reflector member such that saidlight source is at a position between said optical focal point and saidopen end of said reflector member effective for providing a controlleddivergence beam pattern light output which is wide and unfocused inrelation to a narrow, beam pattern light output as occurs when saidlight source is positioned at said optical focal point; and, amulti-stage spacer member disposed in surrounding relation to asubstantial portion of said lead members, said spacer member providingsupport for said lead members and further having at least one segmentwhich can be varied in length.